TITLE: Characterizing the impact of channel stacking patterns and intra-channel heterogeneity on -fluid flow, Laguna Figueroa

MOTIVATION AND OBJECTIVES: Flow-path connectivity in deep-water slope channel reservoirs is controlled by multi-scale stratigraphy including a combination of internal channel architecture and the stacking patterns of channels that form composite channel complexes. Although flow connectivity is inherently three-dimensional, measurements in the subsurface are sparse (wireline logs and core) or low resolution (seismic reflectivity) providing limited information for reliable prediction. We will use outcrop analog studies to fill this gap by quantifying connectivity from the outcrop and calibrating it to three-dimensional connectivity predictions using three-dimensional modeling studies. Questions we will attempt to answer include: Is two-dimensional static connectivity obtained from outcrop a sufficient indicator of three-dimensional flow connectivity? What are the primary controls on three-dimensional flow connectivity in composite channel complexes similar to those at Laguna Figueroa? How much detail must a geomodel include to accurately capture three-dimensional flow connectivity? This project will link objectives 2 (3-D architectural models of reservoir-scale sedimentology) and 3 (reservoir analog Geomodeling and flow simulation) within the overall JIP proposal.

GEOLOGIC CONTEXT: Channel elements of the Tres Pasos Formation exposed near Laguna Figueroa represent an example of mature deep-water slope channels (Fig. A). Previous work by Macauley and Hubbard (2013) revealed eighteen channel elements, synthesized a model for internal channel architecture (Fig. B) and documented channel stacking patterns. These data provide an excellent opportunity to study the controls on flow path connectivity using a combination of architectural and reservoir analog modeling studies.

Images showing a preliminary geomodel from outcrop data. (A) A single channel element tied to the outcrop; (B) Each channel element is comprised of fairly consistent internal architecture that, in this simple model, is represented by four facies: axis, off-axis, margin and bypass drape; and (C) All eighteen, stacked channel elements. 

METHODS AND DATA: In this study we will use the three-dimensional outcrop model (Fig. C) to test: (1) static connectivity; (2) the impact of variable channel width (200 – 300 m); (3) the importance of variations in internal architecture defined as proportion of axis, off-axis, and margin facies; (4) the importance of including detailed internal channel architecture in the geomodel; and (5) the effects of channel base drape continuity and extent (percentage of coverage). We will compare static connectivity metrics in two-dimensions directly from the outcrop exposure, and then compare them to three-dimensional dynamic connectivity using flow simulation. A goal is to elucidate whether static two-dimensional connectivity measures from outcrop are good proxies for three-dimensional dynamic connectivity. Finally, we will tie the three-dimensional connectivity results back to statistics from measured sections to test the ability of one-dimensional statistics to help predict the three-dimensional connectivity and answer the question of how many wells would be required to generate an accurate prediction.